Dynamic recrystallization in a Ni–Ti–Fe shape memory alloy: Effects on austenite–martensite phase transformation

Investigation of Dynamic Recrystallization of NiTi Shape Memory Alloy Subjected to Local Canning Compression

“…According to the aforementioned analysis, it can be deduced that in the present study, DDRX and CDRX coexist during plastic deformation of NiTi SMA at 600 and 700 • C. It has been reported in the literatures that stacking fault energy is not a rigorous factor distinguishing between DDRX and CDRX since DDRX is observed in the metals with high stacking fault energy [18], while CDRX is observed in the metals with low stacking fault energy [19]. It can be generally accepted that DDRX frequently occurs in NiTi-based SMA [6][7][8]. However, recent literature has shown that CDRX is captured in NiTiFe SMA [9].…”

“…Metals 2017, 7,208 according to orientation distribution function (ODF). In addition, it can be found that the misorientation of the grains basically follows a normal distribution except that the grains with the misorientation of 1-2° exhibit a higher frequency, as shown in Figure 1c.…”

“…Metals 2017, 7,208 For the purpose of further understanding DRX mechanisms of NiTi SMA, microstructures of NiTi SMA subjected to local canning compression at the various temperatures were characterized by means of EBSD experiment, as shown in Figure 3. The fractions of the recrystallized grains, the substructures and the deformed grains are captured in NiTi SMA subjected to local canning compression at 600, 700 and 800 °C.…”

“…It is well known that plastic deformation at high temperatures is of great importance in manufacturing the products of NiTi-based SMAs [3][4][5]. In particular, dynamic recrystallization (DRX) frequently occurs during plastic deformation of NiTi-based SMAs at high temperatures [6][7][8][9]. It can be generally accepted that DRX has an influence on the microstructures of metallic alloys, which further have an effect on the mechanical properties [10,11].…”

“…Yin et al studied the mechanisms of DRX in the 50Ti-47Ni-3Fe SMA by means of uniaxial compression tests at the temperatures ranging from 750 to 1050 • C and at the strain rates ranging from 0.01 to 10 s −1 , where continuous dynamic recrystallization (CDRX) was found [6]. Basu et al investigated the DRX in an Ni-Ti-Fe SMA subjected to uniaxial compression at the temperatures of 750, 850 and 950 • C, respectively, and they found that the DRX is able to suppress calorimetric signatures of phase transformations from austenite to martensite [7]. Mirzadeh and Parsa investigated hot compression behavior of 50.5 at % Ni-49.5 at % Ti SMA via flow stress curves at the temperatures ranging from 700 to 1000 • C and at the strain rate of 0.1 s −1 , where the typical single-peak DRX behavior was observed [9].…”